Who is Urania (Ranie) Blackwell, from from The Sandman and what is their importance?

Rainie Blackwell is a superhero. After being exposed to the Orb of Ra, Rainie gains power to manipulate matter at its most basic level. She can create nearly anything she wants out of nothing, at least temporarily. She can perform feats of magnificent power. However, she does not leave her house or talk to anyone. She is on disability, afraid to go out in the world or show herself to other people. Rainie Blackwell wants to die.